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Jan. 30, 2013 — Chimps can learn more efficient ways to use a tool by watching what others do, according to research published Jan. 30 in the open access journalPLOS ONE by Shinya Yamamoto and colleagues from Kyoto University and Kent University, UK. Their study presents the first experimental evidence that chimps, like humans, can watch and learn a group member’s invention of a better technique.

This image is of the “dipping” technique performed by chimpanzee Ayumu. He uses his mouth to insert the tube into the bottle. In form, his technique is identical to the “straw-sucking” technique. However, instead of leaving the tube in and retrieving the juice via sucking, he removes the tube and licks the tip. (Credit: Credit: Citation: Yamamoto S, Humle T, Tanaka M (2013) Basis for Cumulative Cultural Evolution in Chimpanzees: Social Learning of a More Efficient Tool-Use Technique. PLOS ONE 8(1): e55768. doi:10.1371/journal.pone.0055768)

Chimps in the study were provided juice-boxes with a small hole and straws to drink with. One group of chimps used the straws like dipsticks, dipping and removing them to suck on the end, while the other group learned to suck through the straw directly. Learning both techniques required the same cognitive and motor skills, but chimps that drank through the straw got considerably more juice in a shorter amount of time. When the first group of chimps watched either a human or a chimp demonstrate the more efficient ‘straw-sucking’ technique, all of them switched to using this instead.

The study concludes, “When chimpanzees are dissatisfied with their own technique, they may socially learn an improved technique by closely observing a proficient demonstrator.”

According to the authors, their results provide insights into the cognitive basis for the evolution of culture in chimpanzees, and suggest ways that culture could evolve in non-human animals.

The present study was financially supported by grants-in-aid from the Ministry of Education, Culture, Sports, Science and Technology in Japan (MEXT: 20002001, 24000001, and MEXT special grant ”Human Evolution” to T. Matsuzawa) and from Japan Society for the promotion of Science (JSPS: 18-3451, 21-9340, 22800034 and 40585767 to S. Yamamoto).